Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Advanced wireless communication systems achieve greater bandwidth efficiency by partitioning the communication channels into increasingly narrow sub-channels. The receivers, in turn, need to use selective filters in order to separate the different carriers, rendering these systems susceptible to interference created by a frequency mismatch between the transmitter and receiver. A Doppler shift resulting from the motion a transmitter relative to the receiver generates a frequency offset that may become problematic for wireless communication with high-speed vehicles.
Strategies for mitigating Doppler shifts such as adjusting transmission frequency or using rake receivers in the frequency-domain fail to correct the underlying problem, the change in carrier frequency introduced by the relative motion of the transmitting and receiving antennas. The Doppler shift impacts wireless communication most severely in high-speed transportation systems such as High Speed Rail (HSR). HSR communication systems enabling passengers to use their wireless communication devices such as cellular phones typically have a fixed infrastructure that supports wireless communication.